Camera dolly



Jan 24, 1939,

A; w. TONDREAU CAMERA DOLLY Filed Nov. 22, 1935 6 Sheets-Sheet l 1 m III. I

ATTORNEY e sheets-sheet 5 CAMERA DOLLY A. \NqTONDREAU Filed Nov. 22,1955 INVENTOR; 'ALBEQT W TONDQEAU ATTORNE N V pvlllllllllllll Jan. 24,1939.

Jan. 24, 1939.

A. w, TONDREAU CAMERADOLLY Filed Nov. 22, 1955 e Shets-Sheet 5 ATTORNEYJan. 24, 1939. A. TONDREA U 2,1 3

I CAMERAPOLLY- Filed Nov. 22, 1935 6 Sheets-Sheet 6 INVENTOR ALBEQT WFJNDIPEAUH ATTORNEY v I Patented Jan. 24, 1939 UNITED STATES CAMERADOLL! Albert W. Tondreau, Glendale, 01,111., alalgnor to Warner Bros.Pictures, Inc., New York, N. Y., a corporation of Delaware ApplicationNovember 22, 1935, Serial No. 51,178

13 Claims. (Ol. 251-2) This invention relates to a camera dolly or boomfor supporting and transporting a motion picture camera while inoperation preferably for the making of the so-called running shots andthe like.

In photographing moving picture scenes it is often necessary to followthe action by moving the camera along with the actors being photographedor by moving the camera vertically above or below the actors to getcertain desired effects.

In making running shots of this kind it is essential that the camera bemoved smoothly without jarring and that the cameraman be maintained in aconvenient position to operate the camera in any elevated position ofthe camera and whether or not the camera is being raised or loweredduring the photographing operation so that he may always direct hisundivided attention to the operation of the camera during photop n Oneobject of the invention is to, provide a camera dolly wherein a smoothand steady vertical movement is imparted to a camera supported thereby.

Another object of the invention is to enable a cameraman and cameracarried by a cameradolly to be manually raised and lowered.

Another object of the invention is to enable a camera carried by acamera dolly to be lowered to a photographing position close'to thefloor.

Another object is to maintain the cameraman in a convenient positionrelative to the camera regardless of the position of the camera.

The invention contemplates a camera dolly having a wheeled truck onwhich a camera supporting arm is pivoted for movement in a verticaldirection. A seat for'supporting the cameraman is also provided on thecamera supporting arm with linkage for maintaining the seat and camerain parallel relationship regardless of the position of the arm. Suitablegearing is provided to'permit the camera supporting arm to be raised byhand. Counterbalancing springs are provided to counterbalance the weightof the camera and cameraman whereby they may be easily and smoothlyraised or lowered.

The 'wheeled'truck has a U-shaped channel formed therein in the path ofmovement of the camera supporting arm whereby the arm, and consequentlythe camera, may be moved to a lowermost position close to the floor.

For further details of the invention reference may be had to thefollowing specification takenin conjunction with the accompanyingdrawings wherein:

Figs. 1 and 2'illustrate a longitudinal section through a camera dollyconstructed in accordance with the present invention.

Fig. 3 is a perspective view of the camera.

dolly.

Fig. 4 is a bottom plan view looking in the direction of the arrow 4(Fig. 1) and showing the steering trangement.

Fig. 511s a sectional elevationview oi. the fifth wheel arrangement andis taken along the line 5-5 of Fig. 2. g

Fig. 6 is a transverse sectional elevation view of the mechanism forelevating the camera carrying arm and is taken along the line 6-6 ofFig. 1.

Fig. 7 is a fragmentary sectional view taken along the line 'l-'l ofFig. 6.

. Fig. 8 is a transverse sectional view of the rear of the camera dollyand is taken along the line 88 of Fig. 1.

Fig. 9 is a transverse sectional view of the front end of the cameradolly .and is taken along the line 9-3 of Fig. 1.

Fig. 10 is a transverse sectional view through the forward end of thecamera carrying arm and is taken along the line ill-l0 of Fig. l.

Fig. 11 is a transverse sectional view of the eccentric arrangement foradjusting the camera plate about its horizontal axis and is taken alongthe line ll-ii of Fig. 10.

Fig. 12 is a sectional view of the automatic brake for holding thecamera carrying arm in locked position and is taken along the line l2-l2of Fig. 1.

Fig. 13 is a sectional view through one of the anchoring devices forsecuring the ends of the counter-balancing, springs and is taken alongthe line l3-i3 of Fig.4.

Fig. 14 is a fragmentary view of the means for I adjusting the positionof the camera operators seat.

Fig. 15 is a plan sectional view of the link arrangement for moving thefront wheel steering arrangement into operating position and is takenalong the line l5l5 of Fig. 1. a

Fig. 16 is a sectional view taken along the line l6--l6 of Fig.- 15 andshows a means-for moving .the front wheel steering rodinto operatingposiof the adjustable Referring now to Figs. 3, 6, 8, and 9 the cameradolly comprises a main body frame or casting I of irregular outlinewhich has a pair of depending flanges 2 and 3 on either side thereof. Apair of running boards 4 and 5 is provided on either side of the mainbody portion I having downwardly extending flanges 5 and 1 whicharesecured to the flanges 2 and 3 as by bolts 3 and 9. The ends of therunning boards 4 and 5 merge into fender pieces III and II which arealso secured to the main body I.

Camera arm actuating mechanism A housing I2 is provided near the centralportion of the body I and has its forward end open as at I3 to receiveand rotatably support the rear end of a load or camera supporting memberor arm I4. The arm I4, in cross section, is in the shape of an invertedU having downwardly extending flanges I5 and I5 (Figs. 6 and 9). Therear of the arm I4 has a pair of bearing portions I1 and I8 (Fig. 6)which are journaled upon a transverse tubular shaft I9. The shaft I3 ismounted in apertures 20 and 2I provided in the side walls 22 and 23 'ofthe housing I2 and is secured in position by means of end plates 24 and25. Bolts 26 secure the end plates 24 and25 to the end walls of thehousing. The left-hand flange I5 of arm I4 is provided with an enlargedarcuate boss 21 concentric with the tubular shaft I3 (Figs. 1 and 6). Asegmental spur gear 28 constituting a power arm for the load arm I4 hasa similar arcuate boss 29 and is secured to the boss 21 through bolts30. The upper portion of the gear 28 has an aperture 3I therein which ismounted over theshaft I3.

A secondary shaft 32 is provided below and forward of the shaft I3 andis rotatably secured within bearings 33 and 34 provided in the sidewalls 22 and 23 of the housing I2. The ends of the shaft 32 are threadedto receive nuts 35 and 35 which prevent longitudinal movement of theshaft 32. A spur gear 31 is secured to the shaft 32 by means of a key 38and meshes with the segmental gear 28. Also secured to shaft 32 by thekey 38 is a worm gear 33 (Figs. 1, 6 and '7). The gear 33 is engaged bya worm 40 secured by a key H to the lower end of the shaft 42 which isrotatably mounted within bearings 43 and 44.

The bearing 43 is provided on a bottom portion of a floating link 45.Link 45 as shown in Fig. 6 has an aperture 45 at its upper end which isfltted over the shaft I9. The lower end is provided with a bearingportion 41 mounted over the shaft 32. The upper bearing 44 is formed ina separate piece having a flange 48 which rests against an annularshoulder provided on the rear wall 43 of the housing I2 and issecuredthereto by bolts 50. Thrust bearings 5I and 52 are provided near eitherend of the shaft 42 to take up the thrust imposed by the worm 40. Theupper portion of shaft 42 has a disk 53 rigidly secured thereto as by akey 54. A handle 55 (Figs. 1 and 12) is secured to the outer portionthereof as by the threaded connection 55. Rotation of the handle 55 ineither direction, it will be understood, causes angular movement of thearm I4 and consequently vertical motion of the camera.

In order to lock the arm I4 in any angular position and prevent itschanging this position ,due to vibration or added weight, a brakingmechanism generally indicated at I20 (Fig. 12) is provided. As will beseen in Fig. 7, the rear wall 43 of the housing I2 is provided with acircular shoulder I2I adjacent the periphery of the disk 53. The uppersurface I22 of the shoulder I2I serves as a braking surface which isadapted to be engaged by a friction block I23 provided within a notchedportion I24 of the rim of disk 53. The block I23 is adapted to be movedbetween guide surfaces I25 and I25. A lever I21, pivotally mounted upona pin I28, is also provided within the notch I24 and has one end I23engageable with the block I23. The other end I30 of the lever I21 isengaged by a plunger I3I slidably mounted within a longitudinal bearingformed through the handle 55. A compression spring I32, placed over theend I29 of the lever I21, normally holds the brake block I23 intofrictional engagement with the surface I22 of the shoulder I2I. When theplunger I3I is pressed by the thumb of the operator, the brake isreleased to allow rotation of the handle 55.

Referring now to Figs. 1, 3 and 10, the arm I4 has a yoke 59 formed atits forward end. The projections or arms 59a and 59b of the yoke 53 areprovided with threaded apertures 60 and BI through which are screwedbearing studs 52 and 62'. A camera plate 53 is secured to a pair ofvertically extending projections of a yoked member 64 as ,by bolts 54'.Bearings 55 and 55 provided in the member 64 are Journaled over thestuds 62 and 62'. A depending projection on the bottom portion of theyoke 54 extends downward into a bearing 31.

parallel relationship at .all angles of the camera supporting arm I4, Iprovide a link 58 (Figs. 1 and '1). One end of the link 58 has a clevis53 (Fig-7) which is pivotally secured by a pin 53 to the link member 45at a point intermediate its ends. The other end has a similar clevis 10(Figs. 1 and 10) which is pivotally supported adjacent the bearing 61 byan eccentric arrangement 1| which will be described in detailhereinafter. Due to the fact that the center distances between thetubular shaft I9 and pin 69' at one end 'and the bearing 52 andeccentric 1| at the other are normally the same distance apart, thecamera plate 63 will remain in a horizontal position regardless of theposition of the camera arm I4 assuming,

of course, that the dolly is in a horizontal position.

The camera which is shown as being mounted within a soundproof casing 12is preferably mounted upon a camera free-head 13 which allows pivotingof the camera about a horizontal or' vertical axis in respect to thecamera plate 53. A handle 14 is provided to pivot the camera 12.

v Seat'adjustment Along the central portion of the arm I4 is provided aseat arrangement generally indicated at 15 (Figs. 1 and 9) A transversehorizontal shaft 16 is journaled near its ends within bearings 11 and18, provided on the side flanges I5 and I5 of the arm I4. A casting I5is provided having spaced .vertical sockets 30, 30a, and 34b therein.

Depending lugs 3| and H on either side are (Fig. 14). A series of spacedholes 86 is pro-- with a similar serrated face 89 provided on the.

lower, portion of a sleeve member 90. The upper face of the member 90has a pair of diametrically opposed notches 9| into which the extendingends of the pin 81 rest. Thus itgnay be seen that vertical adjustment ofthe seat 82 may be accomplished by inserting the pin 81 within any oneof the holes 86. Also, angular adjustment of the seat 82 in a horizontalplane may be effected by lifting the sleeve 90 from engagement with theserrated edge of the socket, i. e. 80', and rotating it to the desiredposition. If this angular adjustment of the seat 82 is insufllcient tobring the seat in line with the camera 12, the stud 85 may be withdrawnfrom the socket 80 and placed.

within any of the other sockets and, 801). If it is desired to allow theseat 84 to swing freely in a horizontal plane one or more washers (notshown) may be interposed between the serrated faces 88 and 89 thuspreventing a locking engagement.

or sheaves 92 and 93 are rigidly secured to the shaft 32 on either sideof the gears 31 and 39; Cables 98 and 95 are provided which have one oftheir ends secured as at 91 and 98 to the sheaves 92 and 93. The otherends of the cables 94 and 95 are brought around pulleys 99 and I00 andthence are secured by. means of clamps IOI and I02 to the ends of a pairof spring anchors I03 and I04. The pulleys 99 and I00 are rotatablysecured to downwardly extending bosses I05 and I06 (Fig. 8) projectingfrom the rear end of the main body casting I.

Referring now to Fig. 13, each of the anchoring I devices I03 and I04comprises a threaded rod I01 having an eye I08 at its rear end to engageeither of the cables 95 and 96. A threaded member I09 is adiustablysecured along the threaded portion of the rod I01 and has a shoulder H0at its forward end which engages a sleeve III. A hexagonal face I I2provided on the opposite end of the member I09 allows this member to beadjusted by means of a wrench or other suitable tool. The outer surfaceof the sleeve III is provided with a helical groove H3. The ends ofitwill be seen that the springs II4 and H5.

counterbalance the weight of both the camera and the camera man andallow a steady movement of the camera in a vertical direction. I

Steering arrangement Referring to Figs. 4 and 9, the front wheels I34and I35 are journaled upon spindles I36 and I31- having at their innerends vertical apertures I36 and I31 to receive king pins I38 and I39.Brackets I40 and I are sec red tothe flanges 2 and 3 of the main castingI as by bolts I42.

The upper surfaces of the bracket I14 (Fig. 16).

The outer portions of each of the. brackets I40- and MI are providedwith 11188 I43 and I44 having bearingstherein to receive the'ends of theking pins I38 and I89. Pins I 45 are provided to secure the king pinsI38 and I39 to their respectivespindles I36 and I31. v

The rear wheels I46 and I41 (Fig. 8) are journaled upon similar spindlesI48 and I49 having vertical apertures I50 and I5I at their inner ends.

King pins I52 and I53 rotatably support the spindles I48 and I49 withinthe U-shaped ends of an axle I54. Axle I54 is secured at its center to atransversely extending tubular shaft I55 which is journaled at eitherend within bearings I56 and I51 (Figs. 1 and 4) secured to the undersurface of the main casting I. Thus it will be seen that a three pointsuspension is provided to allow for any unevenness of the surface overwhich the wheels are to be moved.

As was stated before, one of the features of the pins I68 and I49 (Fig.4) have securely mounted thereto arms I58 and I59 as by pins I58 and I59'. A tie rod I60 pivotally connects the free I ends of the arms I58and I59 to provide parallel movement of the wheels I46 and I41. Thecentral portion of the link I50 has a clevis member I6I to which ispivotally secured'the end of an arm I62 which in turn is rigidly securedto the bottom of a downwardly extending stub shaft I63. By a pin I63'-(Fig.- 8) the shaft I63 is journaled within a vertically extendingbearing provided through the axle I54 and tubular shaft I55. A sleeveI66, secured to the upper end of the shaft I63, hasa horizontal shaftI65 journaled therein, the. ends of which are secured as by pins I66 toa 'yoke' member I61 of a handle I68. Steering of. the rear wheels isthus accomplished by rotating the handle I68 about the axis of the shaftI63.

The front king pins I38 and I39 are similarly secured to arms I69 andI10 having a tie rod "I connected between their outer ends to provideparallel turning movement. The arm I10 also has 'a projection I12 atright anglesthereto'to which is pivotally connected the end of a rodI13.

slotted arm I 16 formed on the arm I59 and at" right angles thereto. Theslot 116' of the arm I16 is provided at either end with a conicalsurface I11 in which is adapted to seat a similar conical face I18 of asleeve member I19. Sleeve I19 is secured within an aperture provided inthe A shoulder I provided on the interior of the sleeve I19 forms a seatfor a compression spring I8I. The other end of the spring I8I engages awasher I82 secured to one end of a bolt I83 as by a nutI84. The head I85of the bolt I83 engages the lower surface of the arm I16 and urges theconical surface I18 of the sleeve I19 into engagement with the conicalsurface I11 by means of the-spring I8I to prevent disengagement undernormal circumv engaged to allow the sleeve member I19 to be rear wheelsto produce lateral or canting movement of the camera dolly, the rod II3, through the handle I81, is moved into the dotted line position,shown in Fig. 4. In this position, the rotation of the arm I59 willimpart a longitudinal movement to the rod I13 and thus turn the frontwheels I34 and I35 in parallel relation with the rear wheels I46 andI41.

Fifth wheel attachment When it is desired to turn the camera dollywithin a verysmall radius, a fifth wheel arrangement generally indicatedat I88 (Figs. 2 and'5) may be used. A casting I89 is adapted to besecured to the rearward flange I90 of the main casting I as by bolts I9Iand I92. A central portion of the casting I89 is provided with verticalsleeve I93 formed integrally thereon which receives a second sleeve I94having its internal diameter threaded as at I95. A vertical shaft I96 isjournaled within a bearing member I91 having a threaded portion I98 inengagement with the threaded portion I95 of the sleeve I94. A hand wheel256 is provided at the upper end of the member i9l and is securedthereto as by bolts I99. Rotation of the hand wheel 256 causes verticalmovement of the member I91 and shaft I96, through the threaded portionI95, to thus move a pair of wheels 200 and 20| into engagement with thesurface of the floor as shown by the line 202. A shaft 203 having itsends journaled within the wheels 200 and MI has a yoke 204 carriedthereby. Yoke 204 in turn is pivotally secured through a shaft 205 tothe ends of a second yoke 206. Yoke 206 is securely mounted as by a key201 to the lower portion of the shaft I96. A thrust bearing 208 isprovided between the lower end of the member I91 and the shoulder of theyoke 206. The upper portion of they shaft I96 has a bracket 209 securedthereto in which is journaled a horizontal shaft 2I0 having a yoke 2provided thereon similar to the yoke I61. A second handle 2I2 may besecured to the clevis 2 to efl'ect rotation of the wheels 200 and 2Mabout a vertical axis. When the fifth wheel arrangement is to be used,the hand wheel 256 is rotated until a flange I91 on the upper part ofthe member l'll strikes the upper surface of the sleeve I94 so as tosupport the rear end of the camera dolly upon the wheels 200 and 20I andthus raise the wheels I46 and I4! out of engagement with the surface ofthe floor. When the dolly is in this position, it will be seen that thecamera plate 63 will be thrown off its horizontal position. Althoughthis may be compensated for by tilting the camera freehead, it would notbe possible to pan the freehead in a horizontal plane. In order tocompensate for this offsetting of the camera plate 63,1 provide theeccentric arrangement ii (Figs. 10 and 11). An eccentric spindle 2I4having its main body journaled within the bearing'tl provided in theyoke 64 has eccentric bearing-portions 2I5 and 2I6 on either sidethereof which are journaled within the clevis 10 of thelink 68. A handle2" on the eccentric portion 2| 5 allows for rotation of the eccentric tothus change the position of the camera plate 63 in relation to the link68. A locking arrange ment generally indicated at 2I8 is provided tolock the eccentric in either of two positions. A

lever 2 I 9 having an ear 220 provided intermediate its ends ispivotally secured at 22I to the clevis 10. The other end of the lever H9is engaged by tension spring 222 to urge the ear 220 into engagementwith a horizontal slot 223 provided on the end of the eccentric portion2I6 of the eccentrio 2.

Miscellaneous At times it may be desired to elevate the camera dollyabove the floor or to change the horizontal position of the dolly as forexample when it is resting upon an inclined surface. For this reason, Iemploy Jacks 224. 225, 226, and 221 near each of the corners of thecamera dolly. The rear jacks 224 and 225 (Fig.5) comprise threaded rods228 and 229 having feet 230 and 23I thereon. The rods 228 and 229 arethreaded within brackets 232 and 233'provided on either side of thecasting I89. The upper ends of the rods 228 and 229 have hand" wheels228' and 229' provided thereon by means of which the jack may be rotatedso as to raise the rear end of the camera dolly. The jacks 226 and 221at the front of the dolly (Figs. 4 and 9) are similar to those of 224and 225 and are rotatably mounted within apertures provided in thebrackets I40 and HI.

Referring to Figs. 3 and 1'7 a pair of telescopic handles 234 and 235are provided at the base of arm I4 which, when in extended position, areadapted to be grasped by the camera dolly oper'ator to facilitatemovement of the dolly along the floor. The handles are slidablysupported in a tubular casing 236 which is suitably secured to the uppersurface of arm I 4. Split sleeve arrangements 231 and 238 are formed ateither end of the casing 236 and are provided with clamping screwmembers 239 and 240, respectivelyfwhereby the handles 234 and 235 may belocked in any desired position.

Referring now to Fig. 18, adjustable foot rests 24I for the cameraoperator are provided at either side of the arm I4 and are secured toeither of the flanges I5 and I6. A hollow shaft 242 is keyed within anenlarged bearing portion 243 extending transversely within the flangeI5. The outer end of the shaft 242 has a serrated face 244 thereon whichis adapted to be engaged by a similar serrated face provided within abore 245 formed within a step member 246. An internal threaded portion241 of the tubular shaft 242 is engaged by a'bolt 248 having a knob 249on the end thereof. When the step is to be adjusted, the knob 249 isrotated so as to withdraw the bolt an amount sufli'cient to allow theserrated faces 244 to be disengaged and the step rotated. The knob 249is then rotated to clamp the serrated faces 244 into engagement. Theopposite end of the bolt 248 has a screw 249 having an enlarged headthereon secured thereto to prevent complete withdrawal of the bolt 248from the tubular shaft 242.

Having thus described the invention, what is claimed as new and desiredto secure by Letters Patent is:

1. A camera dolly comprising a frame, a load supporting member pivotallymounted on said frame, a power arm connected to said load member, meansfor applying power to said power arm to raise said load member, a drum,an operative auaooa L connection between said drum and said load member,a cable having one end thereof around said drum, and a counterbalancespring connected between the other end of said cable and said frame.

2. In a camera dolly, a frame, a load member pivotally carried by saidframe, means including a worm and worm wheel for raising one end of saidload member, a sheave operatively connected to said worm wheel, a springanchored at one end thereof to said frame, and a cable. secured at oneend thereof to the other end'of said spring and having the other endthereof around said sheave.

3. In a camera dolly, a frame, a load member pivotally carried by saidframe, means including a self locking worm and worm wheel for raisingone end of said load member, a sheave operatively connected to said wormwheel, a spring anchored at one end thereof to said frame, and a cablesecured at one end thereof to the other end of said spring and havingthe other end thereof around said sheave.

4. A camera dolly comprising a frame having horizontal portions, a loadsupporting arm pivotally connected to'said frame, a camera supportingmember pivotally connected to said arm, a link pivotally connected tosaid frame and said camera supporting member in parallel relation tosaid arm adapted to maintain said camera supporting member parallel withsaid frame in all positions of said supporting arm, a. seat supported bysaid arm, and means whereby said seat is maintained parallel to thehorizontal portions of said frame.

5. A camera dolly comprising a frame, a load supporting arm pivotallyconnected to said frame for movement in a vertical direction, a camerasupporting member pivotally connected to said arm for movement in avertical direction, a link pivotally connected to said frame and saidcamera supporting member in spaced parallel relationship to said arm, aseat and a seat supporting member pivotally mounted on said arm formovement in a vertical direction and having anextending portion thereofconnected to said link whereby said camera supporting member and saidseat are adapted to maintain substantially horizontal positions for allpositions of said arm.

6. A camera dolly comprising a supporting frame, a camera supporting armpivotally supported on said frame for movement about a horizontal axis,a camera plate pivotally supported on said arm for movement about ahorizontal axis, a seat pivotally supported on said arm for movementabout a horizontal axis, and link means between said plate, said seatand said frame for retaining said plate and said seat in parallelrelation to said frame in all positions of said arm.

7. A camera dolly comprising a camera supporting arm, means forpivotally supporting said arm for movement about a horizontal axis, acamprojections.

8. In a camera dolly, a supporting frame, a

load supporting arm, a shaft carried by said frame and rotatablysupporting said arm for movement about a horizontal axis, meansincluding a plurality of gears for raising and lowering said arm,

a shaft for one of said gears in spaced relation to said first mentionedshaft and carried by said frame, a link journaledpn both of said shaftsa drive shaft for one-of said gears, and means on said link forrotatably supporting said last mentioned shaft.

9; A camera dolly comprising a supporting frame, a load supporting arm,a shaft carried by said arm for rotatably supporting said arm formovement about a horizontal axis, means including a plurality of gearsfor raisingand lowering saidarm, a shaft for one of said gears in spacedrelation to said first mentioned shaft, means for supporting said lastmentioned shaft on said frame, a link carried by both of saidshafts, adrive shaft for one of said gears, means onsaid link for rotatablysupporting said last mentioned shaft, a camera plate plvotally supportedon said arm for movement about a horizontal axis, and link means betweensaid camera plate and said first mentioned link for retaining saidcamera plate in substantially the same angular relation to saidsupporting frame for all positions of said arm.

10. A camera dolly comprising a frame, means arm is in its lowermostposition whereby the camera supporting end of said arm may be broughtadjacent said supporting surface, a pair of extensible springs on eitherside of said channel and each secured at its forward end to the forwardend of said frame, a pair of sheaves operatively connected to said arm,and a cable interconnecting said sheaves with the rear ends of saidsprings to counterbalance said arm. 11. A camera dolly comprising achassis, front and rear wheels for supporting said chassis from asupporting surface, said chassis having a frame extending between saidfront wheels, a camera supporting arm extending over said frame andbeyond said front wheels, means for pivotally supporting said arm onsaid frame for movement about a horizontal axis, said frame comprising aU shaped channel member having vertical side flanges, a bearing bracketfor each of said front wheels each mounted on one of said side flanges,said channel member having a depressed central portion permittinglowering of the forward end of said arm to a point adjacent-saidsupporting surface.

12. A camera dolly comprising a supporting frame, a camera supportingarm, means for pivotally supporting said arm at one end thereof on saidframe for movement about a horizontal axis, means on the opposite end ofsaid arm adapted to support a camera, means comprising a plurality ofgears for raising and lowering said arm, a supporting shaft for one ofsaid gears, a pair of sheaves on said shaft on either side of said gearand secured in driving relation to said gear, a pair of extensiblesprings each secured at one end thereof to said frame, and a pair ofcables each connected at one end thereof to the unsecured end of arespective one of said springs and having a portion thereof wrappedaround a respective one of said-sheaves.

13. A camera dolly comprising a frame. a camera supporting arm, means onsaid frame for pivotally supporting said arm for movement about ahorizontal axis, means including a plurality oi gears for raising andlowering said arm, a sheave operatively connected to one of said gears,an extensible spring parallel with said frame, means for securing oneend of said spring to said frame adjacent one end oi said frame, apulley carried by said frame adjacent the opposite end of said frame,and a cable secured to the opposite end or said spring and extendingaround said pulley,

said cable having a portion thereof wrapped 5 around saidsheave tocounterbalance said am;

ALBERT w. 'romanmm.

